Miniature circuit breakers are well known in the prior art. An illustrative circuit breaker design is disclosed in U.S. Pat. No. 2,902,560 which is assigned to the same assignee as the present application, and the disclosure in which is incorporated herein by reference. As illustrated in the '560 patent, the basic miniature automatic circuit breaker comprises a base and cover, a line terminal and a load terminal and an electrical circuit therebetween, a stationary contact, a movable contact secured to a contact carrier which is movable between a contact OPEN position and a contact CLOSED position to open or close the electrical circuit, an arc interrupting chamber, an operating mechanism for opening and closing the contacts, and a current responsive trip mechanism which releases the operating mechanism to open the contacts in response to a sustained moderate overload or an instantaneous short circuit.
The assembly of these circuit breakers is often labor intensive and not easily automated. Such circuit breakers include various elements or component assemblies which are not susceptible to convenient automatic assembly. For instance, the components installed in the circuit breaker base include a load terminal welded to a bimetal element having a magnetic yoke welded thereto. A magnetic armature having an ambient temperature compensation bimetal is supported on the magnetic yoke. However, these and other components of the illustrated type of circuit breaker are incapable of being Z-axis assembled into the circuit breaker base.
The miniature circuit breaker illustrated in U.S. Pat. No. 4,616,200, which is also assigned to the assignee of the present application and incorporated herein by reference, represents a design which is better adapted to automated assembly. However, several components of the circuit breaker shown therein are still not particularly adapted for Z-axis assembly. As an example, the temperature compensation bimetal shown in the '200 patent extends beyond the length of the armature element and includes an offset end which obstructs assembly. The presence of such components makes the overall circuit breaker incapable of total Z-axis assembly.
Accordingly, there exists a distinct need for a circuit breaker design which avoids such and other related disadvantages inherent with the design and Z-axis assembly of conventional circuit breakers.